Measuring the analyte concentration in a body fluid is an important procedure for determining the health of a patient and monitoring the progress of an illness or the effectiveness of a treatment. One common procedure is monitoring a patient's blood-glucose concentration level. The traditional glucose-monitoring procedure involves a person lancing a finger to obtain at least 3 microliters (μl) of capillary blood. The capillary blood is then applied to an instrument or analysis device, such as a reagent strip, in which reactions occur. These reactions are usually enzyme mediated and are specific to the analyte of interest. The instrument, which may be a reagent strip, is inserted into a blood-glucose meter for quantification of glucose in the blood sample. The glucose concentration in the blood sample is based on a change in the reflectance of the strip or by the amount of current generated in the instrument.
Traditional glucose monitoring may result in significant discomfort to the individual whose blood is being analyzed due to the volume of blood required for the testing and the site from which a sample is collected. In addition to causing discomfort, the use of needles and lancets typically leaves visible marks at the blood-collection site.
An alternative glucose-monitoring technology known in the art includes providing a significantly less invasive monitoring technique involves the quantification of glucose in interstitial fluid (ISF). This technology allows the gathering of interstitial fluid at an alternate site, such as a forearm of the patient. This is accomplished by creating an aperture of 50 to 400 micrometers (μm) in depth in the epidermis of the patient's skin. This technology involves applying mediation material to the skin surface. The purpose of the mediation material is to convert electromagnetic energy into thermal energy. The depth in which the mediation material penetrates the skin, however, varies between individuals, which affects (a) the efficiency of energy transfer (for forming the aperture), (b) the depth of the formed aperture in the skin, and (c) the pain experienced by the patient. Also, the mediation material may mix with the drawn sample and impact the accuracy of the analysis of the analyte concentration.
This alternative process known in the art usually produces small volumes of fluid that require very refined collection and storage techniques. The process is usually quite painful and may result in long-term scaring. Any loss of sample may result in the need to make a larger aperture, create another aperture, or use more force to obtain a larger sample. Either of these will cause the patient to experience more pain.
Thus, there exists a need for a method and a system for determining an analyte concentration that addresses the above-mentioned problems associated with sample collection and contamination.